U05BA code meaning
Invalid Data Received From Rear Radar Module D
What U05BA means
Rear radar module D is the fourth unit in the rear numbering and is reserved for layouts with an unusually dense sensor set at the back. Neither U05BA nor the matching lost-communication code U02B9 is described by any manufacturer in public, so there are no published thresholds or fitting positions. The code says that module D transmits, but the receiving assistance controller treats its frames as invalid, for instance due to a failed checksum or counter, an implausible status or a sensor that was never coded. Because radar functions such as parking help, exit warning and lane change support can draw on several rear sensors, a single faulty unit usually degrades only part of them. Mercedes-Benz shows for rear modules A and B that calibration rather than replacement is often the cure.
U05BA at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyHard
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U05BA
- Individual rear warnings such as exit warning not available
- Assistance message in the instrument cluster
Common causes of U05BA
- PossibleRear radar D not coded to the vehicle
- PossibleAssistance controller software rejects data from module D
- Less likelyRear radar D internally defective
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Rear radar module d
What each part of U05BA means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| BA | The exact fault in that area. |
What to do next
- Note U05BA and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about U05BA
What does U05BA mean?
U05BA means "Invalid Data Received From Rear Radar Module D". Rear radar module D is the fourth unit in the rear numbering and is reserved for layouts with an unusually dense sensor set at the back. It is a generic code, so it means the same on every make.
Is it safe to drive with U05BA?
U05BA does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U05BA fail an emissions test?
U05BA is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is U05BA to fix?
Difficulty: hard. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will U05BA clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.